The present invention is directed to a diagnostic tool for a motor vehicle and more specifically to a diagnostic tool that implements an open architecture to accommodate new features.
Today, motor vehicles include various electronic control units mounted in the vehicle. The control units may control various systems and/or subsystems within the vehicle. For example, a control unit may control an engine, the transmission, brakes or the steering mechanism. These control units are typically coupled to a variety of sensors and/or actuators.
Handheld diagnostic tools have been utilized to trouble-shoot faults associated with these control units. A typical diagnostic tool has included a microcontroller and an interface circuit to facilitate communication between the microcontroller and the control units in the vehicle. Such tools have also included a non-volatile memory (either internally or externally, i.e., a plug-in module, or both) that stored various routines to enable the tool to communicate with a user and the control units within the vehicle. These routines have been individually compiled and then linked to produce an executable binary, which was then downloaded into the tool's non-volatile memory. In tools using this approach, when one routine required changing or a new diagnostic routine was to be added, each routine was again compiled and linked with the other routines before being downloaded (as a whole) into the tool's non-volatile memory.
Various manufacturers have also marketed handheld computers for non-automotive applications. For example, a personal information manager (PIM) is a pen-based computer that has typically be utilized as a calendar and/or an address book. A personal digital assistant (PDA) or handheld personal computer (HPC) is a handheld device that combines computing, telephone, facsimile and networking features. PDAs and HPCs have normally included an operating system that is compiled and linked separately from any applications. For example, the Windows CE operating system (which is similar to Windows 95) has been implemented in some PDAs. An example of a real-time operating system (RTOS) that has seen some use in handheld computers is the Lynx operating system (LynxOS). The LynxOS is compatible with industry software standards, such as UNIX, and functions on a fairly broad range of hardware platforms (e.g., Intel, IBM, Motorola and Sun Microsystems).
While various handheld devices have utilized an operating system, no motor vehicle diagnostic tool has included an operating system that is compiled and linked separately from a plurality of diagnostic applications (routines).